Role of oxidative stress in various diseases: Relevance of dietary antioxidants

Oxidative stress plays important role in the pathophysiology of various diseases. Oxidative stress is caused in body due to an imbalance between the activities of endogenous pro-oxidative enzymes. Cellular antioxidants are known to change their redox state and they can be targeted for destruction, regulate oxidative processes involved signal transduction, effect gene expression and the pathways of cell proliferation and death. Oxidants and antioxidants play an important role in maintaining a balance between free radicals produced by metabolism or derived from environmental sources and the antioxidant system of the body. A natural antioxidant system exists in the biological systems which is responsible for prevention of damage by pro-oxidants. Impaired endogenous antioxidant system results in accumulation of free radicals, which not only induces lipid peroxidation but also imposes severe stress on the body leading to many diseases such as Alzheimer’s disease, Parkinson disease, Diabetic neuropathy, various cardiovascular diseases. Antioxidant system may be intrinsic or extrinsic. Intrinsic involves body own neutralizing systems and extrinsic antioxidant involves dietary supplements that are taken in the form of food like vitamin C, vitamin E and beta carotene that can be gained from the fruits and vegetables for the prevention and management of diseases induced by free radicals.